I really appreciate the information contained in this thread. However, the thread title is: What's The Name Of The Sealant? ...And I'm not sure the "right stuff" got named?
The ProFlex RV might be the right stuff, but all the links point to several different types of adhesives instead of giving the name.
I can also tell many of you used silicon or some other type of adhesive thinking you got the right stuff, but did you really?
The "white paper" from Winnebago listing part numbers is great to have, but what brand and adhesive type do those part numbers refer to? Further, I doubt Winnebago still supplies these adhesives? ...They might. ...They might not and my experience shows 50%+ of the time Winnebago no longer carries part numbers on record.
My Itasca Horizon (40AD) roof failed last year due to high winds in the El Paso area, right at the start of my 4 month long summer vacation; and so I will share what I learned firsthand -- after much personal experiences on how to repair my roof on the road; where to repair the roof; and my experiences working directly with Winnebago who put a new roof on my RV:
1) High cross winds will attack the front leading edge of your roof and the rear roof area above your bedroom slide. In my case, the fiberglass skin ripped out of the channel just behind the front cap on the driver's side. Then the wind then got under the fiberglass skin and proceed to rip off the roof clear to the rear of the coach. This force left my roof flapping in the wind, which means the skin completely separated it from the glue that holds it to the styrofoam roof sections.
2) I think the roof channel on the passenger side is pretty well protected, but that's because you have a long awning bolted to the sidewalls, and that holds the roof edge down. But the roof channel above the entry door is still vulnerable and you might want to pay particular attention to this area.
3) I found polyurethane sealants like "Quad" (available at HD and Lowes) have excellent adhesion qualities, but are very poor when it comes to UV protection! And UV will cause cracking in 6 months time, which bothered me from a water protection point of view.
4) 100% Silicon adhesives are much better for UV protection, but not strong enough to use on your roof. Therefore, a "Hybrid" sealant needs to be used. But what kind is the question?
5) Prior to Winnebago putting an entire new roof on; and after the wind damage I sustained; I need a quick fix to complete my summer vacation. So I ordered off Amazon 2" Eternabond tape and ran it down the entire driver-side part of the roof. It really stuck and it did not look too bad. (Unfortunately, you cannot get Eternabond in clear.) But I can tell you that if you tape your roof before it fails then you will probably never lose it like I did in the first place.
6) Winnebago would not repair my roof. All they would do is replace it for $35,000; and even then it took 3 months for them to schedule me into their shop. Never mind that Forest City, IA is in the country and about 80 miles to the nearest airport. So there are logistic issues you need to contend with too if you go this route.
7) The good news is that Hartford insurance DID pay for the roof repairs, but their decision was entirely based on the fact that I kept a detailed service records (IN A BOOK); and in those records was an 8 month old entry indicating that I replaced the roof sealant "all around the entire roof."
So had it not been for me maintaining a detailed service record, the insurance company would NOT have paid for this repair. ...And I think I was lucky in that my insurance company only asked for proof that I maintained the roof within the last year, because I understand some insurance companies are asking for proof of roof maintenance within the last 6 months!
So now I have a new roof (with a new inside roof vinyl ceiling too, which is a whole different subject), but I still need to either "maintain" my new roof with the RIGHT SEALANT or I will choose to apply 2" of Eternabond tape to the roof so I never have any wind problems again. But since my roof is new, I probably will wait 3 years before I do this.
Conclusions: The problem is that silicon adhesives are not strong enough to hold the fiberglass skin in the channel; and polyurethane adhesives like Quad have poor UV protection. ...And with enough time all these over the counte
r type adhesives will fail.
So you need to pick the right "Hybrid Sealant" and I don't mean the new stuff by Gorilla Glue. (Although I have been pretty impressed by "Flex Glue" I still can't recommend it at this point.)
What I am sure about is this: 3M makes a 4200 and more permanent 5200 boat sealant, but it's only available in white. So if you can use white then one of these two sealants sound like the right stuff for this application.
If you need a clear sealant, then that is what we all are waiting for and the point of this thread is to NAME THAT SEALANT so we know what to use. And we need a verifiable source to back-up what clear type of sealant is best!
In my mind, I think Eternabond tape is the best solution, but I wish they offered it in a 1" version, but they don't.
And given all I have read about semi-truck aerodynamics, which has to be similar to RV aerodynamics, I don't think you need a ton of glue strength to hold your fiberglass skin inside the channel, due to the vacuum that is created within the 1 foot area covering most of your roof top, but you do need more than what you can get from the best Silicon adhesives. And when you are dealing with crosswinds the aerodynamics change.
On the subject of needing flexibility. Yes, that is very important too. And we all know this is case every time we enter a driveway and torque the "big box" one way and then another. So this is why Winnebago uses a roof trim sealant made to flex.
In closing and for fun, you might like to watch this video on truck aerodynamics: